Front profile shape and tiller

[longbow steve]

Hi Guys, I have been lurking for years admiring your creations and developing my own bow making skills in the mean time. One thing that isn't gelling is the whole front profile to tiller shape corelation. Can someone please explain. I have read the Bowyers Bible section that covers this but would rather not follow blindly. Thanks Steve

[bow101]

I would like to help, I have learned so much and gathered ton's of stuff that I have seriously become Dangerous building bows. Why.? going about it half cocked, most of the time.
But I'am improving..!!!! The one thing I have learned is that Tillering has to be done slowly for Newbies, I broke at least 4 bows by been to Hasty....no fault of the wood what so ever

[RyanY]

Matching tiller shape to the front view profile of a bow allows it so that mass is moving efficiently. For example a pyramid bow should bend in an arc of a circle because the width taper is straight to the tips so each part of the limb should be bending the same amount. A bow with limbs that have a parallel taper for some length should be tillered elliptically. Bows like these have enough width to do more work in the mid and outer limb and should bend more there and also have less width in the inner limb so it should be stiffer. Bows can certainly be tillered without this in mind but moving mass won't be as efficient and the bow will most likely suffer in performance.

[SLIMBOB]

Agree with ryoon.  Del will be along shortly to offer the counter to this however.  He feels as though that the entire "front profile/tiller shape" kerfuffle was handed to early man by some Nordic god to be passed on to future bowyers as a generational curse........Kidding Del.....Well sorta.....kidding.